Until the summer of 2005, Sharon Kaufman had never paid much attention to the shifting theories blaming vaccines for a surge in reported cases of autism. Kaufman, a medical anthropologist at the University of California, San Francisco, knew that the leading health institutions in the United States had reviewed the body of evidence, and that they found no reason to think vaccines had anything to do with autism. But when she read that scientists and public officials who commented on the studies routinely endured malevolent emails, abusive phone calls, and even death threats, she took notice.

“Hecklers were issuing death threats to spokespeople,” Kaufman exclaims, “people who simply related the scientists’ findings.” To a researcher with a keen eye for detecting major cultural shifts, these unsettling events signaled a deeper trend. “What happens when the facts of bioscience are relayed to the public and there is disbelief, lack of trust?” Kaufman wondered. “Where does that lead us?”

Struck by how the idea of a vaccine-autism link continued to gain cultural currency even as science dismissed it, Kaufman took a 26-month hiatus from her life’s work on aging and longevity to investigate the forces fueling this growing divide between scientists and citizens (see Figure 1). She wanted to understand how parents thought about risk and experts, how these attitudes shaped parents’ decisions about vaccination, and what the vaccine wars might teach us about the long-term erosion of public trust in science….